#!/bin/bash

#
# configures aliases of device $1
#
# This script goes out of its way to arrive at the configuration of ip
# aliases described in the ifcfg-$DEV:* and ifcfg-$DEV-range* files from
# whatever existing configuration it may be given: existing aliases not
# specified in the configuration will be removed, netmasks and broadcast
# addrs will be updated on existing aliases, and new aliases will be setup.
#
#   range specification files:
#
# One can specify ranges of alised ipaddress using ifcfg-$DEV-range* files.
# Specify multiple ranges using multiple files, such as ifcfg-eth0-range0 and
# ifcfg-eth0-range1, etc. In these files, the following configuration variables 
# specify the range:
#
#    IPADDR_START    -- ipaddr to start range at. eg "192.168.30.1"
#    IPADDR_END      -- ipaddr to end range at. eg "192.168.30.254"
#    CLONENUM_START  -- interface clone number to start using for this range. eg "0"
#
# The above example values create the interfaces eth0:0 through eth0:253 using
# ipaddrs 192.168.30.1 through 192.168.30.254, inclusive.
#
# Other configuration variables such as NETMASK and BROADCAST may be specified
# in the range file and will apply to all of the ipaddresses in the range. Range
# files also inherit configuration from the ifcfg-$DEV file just like normal.
#
# Note that IPADDR_START and IPADR_END are required to be in the same class-c
# block. I.e. IPADDR_START=192.168.30.1 and IPADDR_END=192.168.31.255 is
# not valid.
#
#   speed with large sets of interfaces:
#
# Considerable effort was spent making this script fast. It can efficiently 
# handle a thousand ip aliases on one interface.
# 
# With large sets of ipaddresses the NO_ALIASROUTING=yes configuration is
# highly recommended. (This can be specified in ifcfg-$DEV and inherited.) This
# prevents this script from setting up routing details for the virtual
# interfaces, which I don't think is needed, because outgoing traffic can use the
# main interface. However, make your own conclusions on what you need.
# 
# My test setup of four class C address blocks on a P166 took 25 seconds of 
# which 16 seconds of this was spent in the ifcconfig calls. Without the 
# NO_ALIASROUTING=yes config an additional 12 seconds is spent in route calls.
#
#   notes on internals:
#
# This script uses the bash "eval" command to lookup shell variables with names
# which are generated from other shell variables. This allows us to, in effect,
# create hashes using the shell variable namesspace by just including the hash
# key in the name of the variable.
#
# This script originally written by: David Harris <dharris@drh.net> 
#                                    Principal Engineer, DRH Internet
#                                    June 30, 1999
#
#            modified by: Bill Nottingham <notting@redhat.com>

TEXTDOMAIN=initscripts
TEXTDOMAINDIR=/etc/locale

device=$1
if [ "$device" = "" ]; then
	echo $"usage: ifup-aliases <net-device> [<parent-config>]\n"
	exit 1
fi

PARENTCONFIG=${2:-ifcfg-$device}
parent_device=$device

cd /etc/sysconfig/network-scripts  
. ./network-functions

# Grab the current configuration of any running aliases, place device info
# into variables of the form:
# rdev_<index>_addr = <ip address>
# rdev_<index>_pb = <prefix>_<broadcast>
# rdevip_<ipaddress> = <index>
# Example:
# rdev_0_addr=192.168.1.1
# rdev_0_pb=24_192.16.1.255
# rdevip_192_168_1_1=0
#
# A list of all the devices is created in rdev_LIST.

eval $( ip addr show $device label $device:* | \
	awk 'BEGIN { COUNT=0;LAST_DEV="" } /inet / {
# Split IP address into address/prefix
                split($2,IPADDR,"/");
# Create A_B_C_D IP address form
                IP_ADDR=IPADDR[1];
                gsub(/\./,"_",IP_ADDR);
# Split device into device:index
                split($NF,DEV,":");
# Update last device
                LAST_DEV=LAST_DEV " " DEV[2];
                printf("rdev_%s_addr=%s\nrdevip_%s=%s\nrdev_%s_pb=%s_%s\nrdev_LIST=\"%s\"\n",
	             DEV[2],IPADDR[1],IP_ADDR,DEV[2],DEV[2],IPADDR[2],$4,LAST_DEV);
	     } END {
	        if(LAST_DEV == "") print "no_devices_are_up=yes"
	     }' );

       #
       # Store configuration of the parent device and network
       #

# read from the /etc/sysconfig/network
eval ` (
       . /etc/sysconfig/network;
       echo network_GATEWAY=$GATEWAY\;;
       echo network_GATEWAYDEV=$GATEWAYDEV\;;
) `

# read defaults from the parent config file
[ -f $PARENTCONFIG ] || {
       net_log $"Missing config file $PARENTCONFIG."
       exit 1
}
eval ` (
       . ./$PARENTCONFIG;
       echo default_PREFIX=$PREFIX\;;
       echo default_NETMASK=$NETMASK\;;
       echo default_BROADCAST=$BROADCAST\;;
       echo default_GATEWAY=$GATEWAY\;;
       echo default_NO_ALIASROUTING=$NO_ALIASROUTING\;;
       echo default_ARPCHECK=$ARPCHECK\;;
) `
[ -z "$default_GATEWAY" ] && default_GATEWAY=$network_GATEWAY

function ini_env ()
{
       DEVICE=""
       IPADDR=""
       PREFIX=$default_PREFIX
       NETMASK=$default_NETMASK
       BROADCAST=$default_BROADCAST
       GATEWAY=$default_GATEWAY
       NO_ALIASROUTING=$default_NO_ALIASROUTING
       ONPARENT=""
       ARPCHECK=$default_ARPCHECK
}

function is_default_gateway ()
{
	LC_ALL=C /sbin/ip route ls default scope global \
		| awk '$3 == "'"$1"'" { found = 1; } END { exit found == 0; }'
}

       #
       # Read the alias configuration files and enable each aliased
       # device using new_interface()
       #

function new_interface ()
{

       ipa=$IPADDR; ipb=${ipa#*.}; ipc=${ipb#*.};
       IPGLOP="${ipa%%.*}_${ipb%%.*}_${ipc%%.*}_${ipc#*.}";
       DEVNUM=${DEVICE#*:}

       MATCH='^[0-9A-Za-z_]*$'
       if (LC_ALL=C; [[ ! "$DEVNUM" =~ $MATCH ]]); then
	      net_log $"error in $FILE: invalid alias number"
	      return 1
       fi

       eval "
              ipseen=\$ipseen_${IPGLOP}; devseen=\$devseen_${DEVNUM};
              ipseen_${IPGLOP}=$FILE; devseen_${DEVNUM}=$FILE;
       ";

       if [ -n "$ipseen" ]; then
              net_log $"error in $FILE: already seen ipaddr $IPADDR in $ipseen"
	      return 1
       fi

       if [ -n "$devseen" ]; then
              net_log $"error in $FILE: already seen device $parent_device:$DEVNUM in $devseen"
	      return 1
       fi

       if [ -z "$DEVICE" -o -z "$IPADDR" ]; then
              net_log $"error in $FILE: didn't specify device or ipaddr"
	      return 1
       fi

       if [ -z "$NETMASK" -a -z "$PREFIX" ]; then
               net_log $"error iN $FILE: didn't specify netmask or prefix"
       fi

       if [ -z "$PREFIX" ]; then
               eval $(/bin/ipcalc --prefix ${IPADDR} ${NETMASK})
       fi

       if [ -z "$BROADCAST" -o "$BROADCAST" = "$default_BROADCAST" ]; then
               eval $(/bin/ipcalc --broadcast ${IPADDR}/${PREFIX})
       fi

       if [ "$no_devices_are_up" = "yes" ]; then
               setup_this=yes
       else

               setup_this=""

               eval "
                       rdev_addr=\$rdev_${DEVNUM}_addr;
                       rdev_pb=\$rdev_${DEVNUM}_pb;
                       rdev_mark=\$rdev_${DEVNUM}_mark;
                       rdevip=\$rdevip_${IPGLOP};
               ";

               if [ -n "$rdev_addr" ]; then
                       if [ "$rdev_addr" = "${IPADDR}" ]; then
                               newmark=keep
                               if [ "$rdev_pb" != "${PREFIX}_${BROADCAST}" ]; then
                                       setup_this=freshen
                               else
                                       setup_this=no
                               fi
                       else
                               if [ "$rdev_mark" != "remove" ]; then
                                       /sbin/ip addr flush dev $parent_device label $parent_device:${DEVNUM}
                                       do_netreport=yes
                               fi
                               newmark=remove
                               setup_this=yes
                       fi
                       if [ -n "$rdev_mark" -a "$rdev_mark" != "$newmark" ]; then
                               net_log $"error in ifcfg-${parent_device}: files"
			       return 1
                       fi
                       eval " rdev_${DEVNUM}_mark=\$newmark ";
               else
                       setup_this=yes
               fi

               if [ -n "$rdevip" -a "$rdevip" != "${DEVNUM}" ]; then
                       eval " mark_remove=\$rdev_${rdevip}_mark ";
                       if [ -n "$mark_remove" -a "$mark_remove" != "remove" ]; then
                               net_log $"error in ifcfg-${parent_device}: files"
			       return 1
                       fi
                       if [ "$mark_remove" != "remove" ]; then
                               eval " rdev_${rdevip}_mark=remove ";
                               /sbin/ip addr flush dev $parent_device label $parent_device:$rdevip
                               do_netreport=yes
                       fi
               fi

       fi

       if [ "$setup_this" = "freshen" ] ; then
               # we can do the freshen stuff right now
               /sbin/ip addr change ${IPADDR}/${PREFIX} brd ${BROADCAST}
       fi

       if [ "$setup_this" = "yes" ] ; then
               if [ "${parent_device}" != "lo" ] &&  [ "${ARPCHECK}" != "no" ] && \
               is_available ${parent_device} && \
               ( grep -qswi "up" /sys/class/net/${parent_device}/operstate ||  grep -qswi "1" /sys/class/net/${parent_device}/carrier ) ; then
                   echo $"Determining if ip address ${IPADDR} is already in use for device ${parent_device}..."
				   /sbin/arping -q -c 2 -w ${ARPING_WAIT:-3} -D -I ${parent_device} ${IPADDR}
				   if [ $? = 1 ]; then
					   net_log $"Error, some other host already uses address ${IPADDR}."
					   return 1
				   fi
			   fi

               /sbin/ip addr add ${IPADDR}/${PREFIX} brd ${BROADCAST} dev ${parent_device} label ${DEVICE}

	       [[ "$IPV6INIT" != [nN0]* ]]  && /etc/sysconfig/network-scripts/ifup-ipv6 ${DEVICE}

               if [ "$NO_ALIASROUTING" != yes ]; then

                       GATEWAYDEV=$network_GATEWAYDEV;

                       if [ -n "${GATEWAY}" -a \
			       \( -z "${GATEWAYDEV}" -o "${GATEWAYDEV}" = "${DEVICE}" \) ]; then
                               # set up default gateway, if it isn't already there
			       if ! is_default_gateway "$GATEWAY"; then
					ip route replace default ${METRIC:+metric $METRIC} via ${GATEWAY} dev ${DEVICE}
			       fi
                       fi

		       /etc/sysconfig/network-scripts/ifup-routes ${DEVICE} ${NAME}

                       do_netreport=yes
                       ifuplocal_queue="$ifuplocal_queue $DEVICE"

               fi

	fi

}

if [ "$BASH_VERSINFO" ]; then shopt -s nullglob; else allow_null_glob_expansion=foo; fi

for FILE in ifcfg-${parent_device}:* ; do
       is_ignored_file "$FILE" && continue
       ini_env;
       . ./$FILE;
       [ -z "$DEVICE" ] && DEVICE=${FILE##ifcfg-}
       [ "$ONPARENT" != "no" -a "$ONPARENT" != "NO" ] && new_interface;
       unset DEVICE
done

for FILE in ifcfg-${parent_device}-range* ; do
       is_ignored_file "$FILE" && continue
       ini_env;
       . ./$FILE;

       ipaddr_prefix=${IPADDR_START%.*}
       ipaddr_startnum=${IPADDR_START##*.}
       ipaddr_endnum=${IPADDR_END##*.}

       if [ "${IPADDR_START%.*}" != "${IPADDR_END%.*}" ]; then
               net_log $"error in $FILE: IPADDR_START and IPADDR_END don't agree"; continue
       fi

       if [ $ipaddr_startnum -gt $ipaddr_endnum ]; then
               net_log $"error in $FILE: IPADDR_START greater than IPADDR_END"; continue
       fi

       ipaddr_num=$ipaddr_startnum
       ipaddr_clonenum=$CLONENUM_START

       while [ $ipaddr_num -le $ipaddr_endnum ]; do
               IPADDR="$ipaddr_prefix.$ipaddr_num"
               DEVICE="$parent_device:$ipaddr_clonenum"
	       [ "$ONPARENT" != "no" -a "$ONPARENT" != "NO" ] && new_interface;
               ipaddr_num=$(($ipaddr_num+1))
               ipaddr_clonenum=$(($ipaddr_clonenum+1))
       done
       
done

       #
       # Remove any devices that should not be around
       #
	for DEVNUM in $rdev_LIST ; do
	       eval " rdev_mark=\$rdev_${DEVNUM}_mark ";
	       if [ -z "$rdev_mark" ]; then
	               /sbin/ip addr flush dev $parent_device label $parent_device:${DEVNUM}
        	       do_netreport=yes
	       fi
	done
       #
       # Notify of new device creation
       #

if [ -n "$do_netreport" ]; then
       do_netreport
fi

if [ -x /sbin/ifup-local ]; then
       for DEVICE in $ifuplocal_queue ; do
               /sbin/ifup-local ${DEVICE}
       done
fi
